1 2 3 4 6 7 8 11 12 13 14 15 16 17 An understanding of regional differences in countries where the population is spread across large distances is relevant for health care planning. Potentially risk factors may differ across a country resulting in the need to address mental health needs on a regional basis rather than centrally. Furthermore, an understanding of geographic variability permits allocation of resources to be distributed in a proportional basis by need. 18 20 Population studies about psychiatric disorders in Latin America, as well as other developing regions of the world, are rare. They are important, however, for understanding variations in patterns of disorders, underlying determinants, and service needs. Chile, given its rather extraordinary geography provides an important test of variations in disorder rates across a spatially dispersed population, and offers perhaps the best case example of a country where national rates would seemingly have low value for estimating the need for mental health services and programs. 2 Methods Sample selection 21 2 P Diagnostic assessment 22 23 24 25 26 Interviewers and training Social science university students in their senior year underwent training following the WHO protocol at the University of Concepcion, a WHO CIDI training and reference center. The 64 interviewers received over 80 h of instruction and practice sessions. Each interviewer had to conduct practice interviews with volunteer adult subjects with and without psychiatric disorders selected from local clinics, as well as a pilot interview on an individual in a non-selected household in the community. Approximately 80% of the interviews were audiotaped following the subject’s consent, and 20% randomly reviewed for quality control. Analysis procedures 27 Results 1 2 P 2 P Table 1 Socio-demographic characteristics by region Disorders N N N N 2 df P % SE % SE % SE % SE Gender   Male 48.2 1.0 46.4 1.4 48.9 1.0 47.4 1.5 3.23 3 0.38   Female 51.8 1.0 53.6 1.4 51.1 1.0 52.6 1.5    Age   15–24 26.7 1.6 24.9 2.1 27.3 2.3 27.0 7.4 7.3 15 0.94   25–34 25.4 1.6 26.1 1.4 27.1 0.6 23.2 4.6      35–44 18.2 1.9 18.5 1.1 21.1 2.0 17.5 2.6      45–54 12.1 1.4 12.8 1.2 11.8 0.4 12.3 1.2      55–64 9.0 1.4 9.2 0.8 6.5 0.4 9.8 1.3      65+ 8.7 2.3 8.5 1.0 6.2 1.9 10.4 1.7    Education   No education 2.7 1.0 1.1 0.2 0.3 0.2 1.3 1.0 11.13 9 0.31   Basic 19.7 3.8 17.9 2.3 7.8 2.0 15.2 7.6      Medium 52.3 3.3 47.9 1.6 52.7 1.5 38.2 7.3      High 25.2 7.1 33.2 2.3 39.1 3.2 45.2 15.4    Marital status   Married 54.7 2.8 52.8 2.3 53.7 3.2 52.3 5.8 25.31 12 0.05   Widowed 5.2 1.1 4.7 0.7 3.3 1.3 5.8 0.2      Separated/anulled 1.7 0.7 4.1 0.5 3.3 1.4 2.0 0.6      Never Married 34.4 1.9 32.6 2.4 33.9 1.1 36.1 8.0      Common Law 4.0 0.8 5.8 1.0 5.9 0.6 3.8 2.0    Income   U$100–U$400 70.5 7.1 54.5 3.9 12.2 4.8 47.7 15.4 67.96 9 0.0001   U$401–U$800 19.3 3.3 21.9 1.8 29.6 2.5 20.6 4.5      U$801–U$1500 6.9 1.9 11.9 1.3 35.6 3.3 12.5 4.0      U$1501+ 3.3 2.5 11.7 2.8 22.7 3.6 19.2 7.2    Urban/rural   Urban 97.3 3.1 99.2 0.9 98.9 1.4 92.3 5.0 3.1 3 0.39   Rural 2.7 3.1 0.8 0.9 1.1 1.4 7.7 5.0    2 3 2 P 2 P 2 P 2 P 2 P 2 P 2 P 2 P Table 2 Lifetime prevalence rates of DSM-III-R disorders by region  Bio Bio Metropolitana Tarapaca Araucania   Disorders % SE % SE % SE % SE 2 P Affective disorders     Major depressive episode 7.1 1.3 11.6 0.8 17.2 2.4 9.8 0.8 9.76 0.04     Manic episode 2.2 0.7 1.4 0.4 1.8 0.3 1.5 1.3 1.11 0.78     Dysthmia 7.5 1.1 7.3 1.2 12.2 1.7 6.0 3.3 3.65 0.32     Any affective disorder 13.6 2.2 15.4 1.2 23.2 1.9 14.0 3.2 3.88 0.30 Anxiety disorders     Panic disorder 1.2 0.6 1.3 0.3 4.3 0.8 1.1 0.5 1.16 0.77     Agoraphobia without panic 14.2 2.7 9.8 1.3 9.7 1.8 5.3 0.8 5.46 0.16     Generalized anxiety disorder 1.8 0.7 3.7 0.5 2.0 0.4 3.0 0.6 5.13 0.19     Any anxiety disorder 19.2 3.7 14.8 1.6 17.9 1.7 8.6 0.9 6.79 0.11 Substance use disorders     Alcohol abuse 2.8 0.8 2.0 0.5 16.9 2.6 7.2 1.4 8.20 0.06     Alcohol dependence 7.0 1.7 6.4 0.8 6.3 0.5 5.0 0.8 3.63 0.32     Drug abuse 0.6 0.3 1.5 0.4 2.4 0.5 0.1 0.1 8.59 0.05     Drug dependence 2.2 0.7 3.3 1.0 2.2 0.3 1.2 0.1 7.72 0.07     Nicotine dependence 2.9 0.6 2.1 0.6 6.5 0.2 5.4 1.0 7.86 0.07     Any alcohol or drug use disorder 11.0 1.8 11.2 1.0 24.3 2.9 12.3 1.8 1.94 0.59     Any substance use disorder 13.0 2.0 12.9 1.1 29.6 2.9 14.6 1.7 2.43 0.50 Other disorders     Non-affective psychosis 2.1 0.6 2.3 0.5 0.8 0.2 0.1 0.0 11.45 0.02     Somatoform disorder 2.7 1.1 4.4 0.8 3.1 0.6 3.5 0.7 1.75 0.63     Cognitive disorder 4.5 1.8 3.7 0.8 0.7 0.8 1.0 0.4 5.70 0.15 Any CPPS disorder 32.2 4.1 30.8 1.6 44.4 1.9 28.9 3.1 2.51 0.49 Female Affective disorders     Major depressive episode 7.1 1.3 15.2 1.4 20.6 0.8 11.2 1.1 11.76 0.02     Manic episode 2.6 1.0 1.8 0.5 3.0 0.6 0.5 0.5 3.62 0.32     Dysthmia 10.7 2.0 11.6 1.9 17.2 1.3 8.7 5.1 2.43 0.50     Any affective disorder 16.4 2.6 21.0 1.7 28.3 0.9 16.0 4.9 3.60 0.32 Anxiety disorders     Panic disorder 1.7 0.9 2.1 0.5 6.7 1.2 2.1 0.9 1.15 0.77     Agoraphobia without panic 20.3 3.2 13.6 2.0 12.2 0.2 7.0 2.4 4.88 0.20     Generalized anxiety disorder 2.5 1.0 6.4 1.0 3.8 0.8 4.4 0.4 5.98 0.13     Any anxiety disorder 26.4 3.9 20.9 2.5 24.8 2.1 12.3 2.0 5.19 0.18 Substance use disorders     Alcohol abuse 0.5 0.4 1.1 0.6 2.6 0.4 1.0 0.4 2.06 0.57     Alcohol dependence 1.7 0.7 2.0 0.7 4.2 0.2 0.4 0.2 7.53 0.07     Drug abuse 0.0 0.0 0.8 0.3 2.3 0.5 0.0 0.0 7.38 0.08     Drug dependence 2.4 0.7 5.0 1.6 2.7 0.4 0.2 0.2 6.86 0.10     Nicotine dependence 2.5 0.7 2.3 0.8 10.0 0.6 2.6 0.4 2.45 0.49     Any alcohol or drug use disorder 3.6 0.9 7.1 1.5 6.9 0.6 1.6 0.6 11.80 0.02     Any substance use disorder 5.9 1.4 8.9 1.4 16.5 0.3 4.1 0.7 10.88 0.02 Other disorders     Non-affective psychosis 2.4 0.7 1.9 0.6 1.6 0.3 0.1 0.1 7.81 0.07     Somatoform disorder 2.4 0.7 5.3 1.1 3.6 0.7 4.4 1.7 4.10 0.27 Any CPPS disorder 35.6 3.8 34.7 2.5 37.8 1.1 23.4 4.0 3.02 0.40 Male Affective disorders     Major depressive episode 7.1 1.5 7.4 1.3 13.6 4.6 8.3 1.5 6.84 0.10     Manic episode 1.8 1.0 1.0 0.4 0.5 0.6 2.6 2.2 1.18 0.76     Dysthmia 4.0 1.0 2.4 0.6 7.1 3.3 3.1 2.0 4.10 0.27     Any affective disorder 10.5 2.2 9.0 1.4 18.0 4.3 11.8 2.9 14.57 0.01 Anxiety disorders     Panic disorder 0.7 0.5 0.4 0.2 1.8 0.3 0.0 0.0 4.39 0.24     Agoraphobia without panic 7.7 2.9 5.3 1.9 7.2 3.5 3.5 1.0 3.94 0.28     Generalized anxiety disorder 1.0 0.7 0.7 0.4 0.0 0.0 1.3 1.0 1.83 0.61     Any anxiety disorder 11.5 4.4 7.9 1.7 10.6 3.4 4.5 0.5 7.59 0.07 Substance use disorders     Alcohol abuse 5.3 1.5 3.0 0.8 31.9 5.6 14.1 2.8 9.17 0.04     Alcohol dependence 12.5 3.7 11.6 1.9 8.4 1.2 10.2 1.8 1.11 0.77     Drug abuse 1.1 0.7 2.4 0.8 2.6 0.6 0.2 0.2 6.93 0.09     Drug dependence 1.9 1.1 1.5 0.6 1.6 0.4 2.3 0.5 1.40 0.71     Nicotine dependence 3.2 0.7 1.9 0.9 2.9 0.5 8.6 2.2 6.05 0.13     Any alcohol or drug use disorder 18.9 4.1 15.9 1.9 42.6 6.3 24.3 3.4 4.83 0.20     Any substance use disorder 20.5 4.3 17.6 2.1 43.3 5.8 26.2 2.9 5.55 0.16 Other disorders     Non-affective psychosis 1.8 1.1 2.7 1.1 0.0 0.0 0.0 0.0 5.78 0.14     Somatoform disorder 3.0 1.7 3.2 1.3 2.6 0.5 2.6 0.9 0.23 0.97 Any CPPS disorder 28.5 5.3 26.4 2.3 51.2 4.0 35.0 5.0 4.46 0.23 Non-affective psychosis includes schizophrenia, schizophreniform disorder, schizoaffective disorder, delusional disorder, and atypical psychosis 2 Table 3 12-Month prevalence rates of DSM-III-R disorders by region  Bio Bio Metropolitana Tarapaca Araucania   Disorders % SE % SE % SE % SE 2 P Total Affective disorders     Major depressive episode 4.1 0.9 7.8 0.8 10.3 1.9 5.1 1.1 8.78 0.05     Manic episode 1.9 0.7 1.1 0.3 1.8 0.3 1.0 0.9 2.05 0.57     Dysthmia 3.0 0.7 4.1 1.2 7.9 2.2 3.1 2.2 6.10 0.13     Any affective disorder 7.8 1.6 10.8 1.3 15.0 1.6 7.5 2.9 5.19 0.18 Anxiety disorders     Panic disorder 0.5 0.3 0.4 0.2 4.1 0.9 0.6 0.6 1.32 0.73     Agoraphobia without panic 7.0 1.8 6.1 1.5 7.5 2.0 2.2 0.9 4.44 0.24     Generalized anxiety disorder 1.2 0.5 2.3 0.6 1.1 0.3 1.7 0.5 2.41 0.50     Any anxiety disorder 11.1 1.7 9.2 1.6 11.9 1.6 3.8 1.3 5.69 0.15 Substance use disorders     Alcohol abuse 2.1 0.6 1.8 0.5 5.8 1.8 3.3 0.8 4.05 0.28     Alcohol dependence 5.2 1.5 4.8 0.7 3.7 0.4 2.8 0.5 4.26 0.26     Drug abuse 0.2 0.2 0.4 0.2 1.5 0.4 0.0 0.0 3.99 0.28     Drug dependence 1.5 0.8 1.9 0.5 1.8 0.3 0.4 0.4 2.91 0.42     Nicotine dependence 2.1 0.5 1.9 0.6 5.6 0.3 4.4 1.0 4.18 0.26     Any alcohol or drug use disorder 8.4 1.6 7.9 0.9 10.7 2.0 6.2 1.2 2.84 0.43     Any substance use disorder 10.0 1.6 9.4 1.0 15.7 2.1 8.2 1.6 2.38 0.51 Other disorders     Non-affective psychosis 1.1 0.4 1.4 0.3 0.8 0.2 0.0 0.0 8.45 0.06     Somatoform disorder 1.8 0.8 3.9 0.6 3.1 0.6 3.0 0.6 2.95 0.42 Any CPPS disorder 23.9 3.5 23.0 1.5 25.3 1.7 14.7 3.9 2.84 0.43 Female Affective disorders     Major depressive episode 4.8 0.9 10.5 1.3 14.8 0.8 5.3 2.4 10.08 0.03     Manic episode 2.6 1.0 1.5 0.5 3.0 0.6 0.2 0.2 6.25 0.12     Dysthmia 4.3 1.4 6.9 2.3 8.8 1.7 3.9 3.2 6.92 0.09     Any affective disorder 9.6 1.8 15.2 2.2 20.0 0.9 8.2 5.3 5.72 0.15 Anxiety disorders     Panic disorder 0.5 0.3 0.6 0.3 6.6 1.3 1.0 1.2 1.37 0.71     Agoraphobia without panic 11.9 3.0 8.4 2.4 10.4 0.3 3.4 1.0 5.78 0.14     Generalized anxiety disorder 1.4 0.8 3.9 1.0 2.2 0.6 2.7 0.7 3.24 0.37     Any anxiety disorder 17.3 2.3 13.0 2.5 17.5 1.2 6.3 1.7 5.90 0.14 Substance use disorders     Alcohol abuse 0.5 0.4 1.0 0.5 0.9 0.2 0.6 0.5 0.93 0.82     Alcohol dependence 0.9 0.5 1.3 0.7 4.2 0.2 0.0 0.0 5.16 0.18     Drug abuse 0.0 0.0 0.2 0.2 0.5 0.1 0.0 0.0 2.48 0.49     Drug dependence 1.5 0.7 2.9 0.8 2.7 0.5 0.2 0.2 8.50 0.05     Nicotine dependence 2.0 0.7 2.1 0.8 8.5 0.4 2.0 0.8 1.71 0.64     Any alcohol or drug use disorder 2.9 1.0 4.5 0.8 5.1 0.4 0.8 0.7 7.98 0.06     Any substance use disorder 4.9 1.4 6.0 0.6 13.3 0.9 2.8 0.7 14.74 0.01 Other disorders     Non-affective psychosis 1.5 0.7 1.2 0.5 1.6 0.3 0.0 0.0 7.05 0.09     Somatoform disorder 1.9 0.7 5.0 1.1 3.6 0.7 4.2 1.8 4.50 0.23 Any CPPS disorder 23.4 2.7 24.7 2.9 28.4 0.9 12.3 5.1 2.83 0.42 Male Affective disorders     Major depressive episode 3.4 1.1 4.7 1.1 5.5 3.6 5.0 0.4 1.30 0.73     Manic episode 1.1 0.9 0.7 0.3 0.5 0.6 1.8 1.6 0.68 0.88     Dysthmia 1.6 0.8 0.8 0.3 7.0 3.3 2.1 2.0 4.78 0.21     Any affective disorder 5.9 1.7 5.7 1.1 9.8 2.8 6.7 1.3 4.46 0.23 Anxiety disorders     Panic disorder 0.6 0.4 0.2 0.2 1.6 0.4 0.0 0.0 3.07 0.39     Agoraphobia without panic 1.7 0.9 3.4 1.7 4.5 3.8 0.9 0.9 1.94 0.59     Generalized anxiety disorder 1.0 0.6 0.4 0.2 0.0 0.0 0.5 0.4 1.97 0.58     Any anxiety disorder 4.4 1.8 4.7 1.6 6.1 3.5 1.1 0.9 3.26 0.37 Substance use disorders     Alcohol abuse 3.7 1.2 2.7 0.8 10.9 3.7 6.3 1.2 6.20 0.12     Alcohol dependence 9.7 2.8 8.8 1.8 3.1 1.0 5.9 0.9 3.88 0.29     Drug abuse 0.4 0.4 0.7 0.5 2.6 0.6 0.0 0.0 3.47 0.34     Drug dependence 1.5 1.2 0.8 0.5 0.9 0.2 0.6 0.8 0.33 0.95     Nicotine dependence 2.2 0.7 1.8 0.8 2.5 0.5 7.0 2.0 3.08 0.39     Any alcohol or drug use disorder 14.4 3.2 11.8 2.0 16.6 4.4 12.1 1.6 1.25 0.74     Any substance use disorder 15.4 3.2 13.3 2.1 18.2 4.0 14.1 2.8 1.07 0.78 Other disorders     Non-affective psychosis 0.8 0.4 1.6 0.7 0.0 0.0 0.0 0.0 5.75 0.14     Somatoform disorder 1.6 1.2 2.6 1.0 2.6 0.5 1.8 0.8 2.05 0.57 Any CPPS disorder 21.8 5.3 20.5 2.5 22.0 3.0 17.3 3.4 1.12 0.77 Non-affective psychosis includes schizophrenia, schizophreniform disorder, schizoaffective disorder, delusional disorder, and atypical psychosis 2 Table 4 Mental health service utilization in the past 6-months by region among those with DSM-III-R 12-month prevalent disorder  Bio Bio Metropolitana Tarapaca Araucania   Disorders % SE % SE % SE % SE 2 P Any MH service 17.6 1.1 21.1 2.5 25.9 0.3 12.0 1.9 10.09 0.03 Non-specialized MH service 15.2 1.0 17.1 1.8 24.3 0.4 10.7 1.6 12.63 0.02 Specialized MH service 5.2 0.9 6.7 1.3 5.6 1.1 3.4 1.1 4.26 0.26 Substance service 0.1 0.1 0.3 0.2 0.4 0.1 0.1 0.1 2.87 0.43 2 Non-Specialized MH Services = primary care physicians; Specialized Mental Health Services = inpatient or outpatient services provided by a psychiatrist or a psychologist or formal substance abuse services; Substance abuse services included inpatient and outpatient detoxification or Alcoholics Anonymous Using logistic regression controlling for socio-demographic variables the regional differences for major depression were maintained for both lifetime and 12-month prevalence, as well as among females in both prevalence periods. Males with lifetime prevalent affective disorders were also at increased risk in Tarapaca. In addition regional differences in lifetime prevalence for alcohol abuse, drug abuse, and nicotine dependence were found. Among females, regional differences in lifetime prevalence were noted for drug abuse, drug dependence, any alcohol or drug use disorder, and cognitive disorders, and among men alcohol abuse with increased risk among those residing in Tarapaca. The statistical differences in regional lifetime prevalence of non-affective psychosis for both genders combined, and females in both prevalence periods, persisted with the rates for Araucania remaining low. As the rates for not only major depression, but also alcohol and drug use disorders were elevated in Tarapaca, additional analyses were conducted controlling for comorbidity in the logistic regressions, the regional differences noted were not altered. 2 P 2 P 4 When urban versus rural was examined across all sites no statistical differences in the rates of disorders were noted. In addition, there were no socio-demographic differences. The sample size of the rural population was small, 203. Discussion 28 The utilization of health service was lowest in Araucania and Bio Bio. This may be consistent with the inequities in availability and access that do exist in health and mental health resources across different regions of Chile. The southern half of the country is the poorest and has the least resources; therefore, the lower rates may be due to a lack of access rather than demand. For example across the regions the number of available mental health beds 2001 in the public health service per 100,000 were Araucania 2.2; Bio Bio 4.8; Metropolitana 34.2; and Tarapaca 47.2. The number of primary care physicians per 100,000 populations also was lowest in Araucania, 57.0, compared to Bio Bio with 169.7, Tarapaca with 61.6 and Metropolitana with 185.8. It could be argued that these regional differences are simply artifact due to sampling differences. Clearly the population investigated in Tarapaca is small for a prevalence study and may have resulted in rates that may prove unstable. Another potential limitation is that the four regions were investigated sequentially, with the potential for socio-cultural influences to impact on the rates during the intervals between data collection. The high proportion of low-income individuals in the Bio Bio sample in comparison to the other sites and in particular Aracucania, the poorest region of the country, reflects the improved economic conditions in Chile during the course of data collection and supports a cohort effect. A cohort effect, however, is highly unlikely to explain the rates of psychopathology given that data collection was obtained from Araucania last, yet it has the highest rate of major depressive disorder. Conclusion 6 29